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Computing the Shapley value in allocation problems: Approximations and bounds, with an application to the Italian VQR research assessment program 23

Computing the Shapley value in allocation problems: Approxim...

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23rd RCRA International Workshop on Experimental Evaluation of Algorithms for Solving Problems with Combinatorial Explosion, RCRA 2016

作者： Lupia, Francesco Mendicelli, Angelo Ribichini, Andrea Scarcello, Francesco Schaerf, Marco Dept. of Computer Science Modeling Electronics and Systems Engineering University of Calabria Rende87036 Italy Dept. of Physics Sapienza University Rome00185 Italy Dept. of Computer Control and Management Engineering Antonio Ruberti Sapienza University Rome00185 Italy

In allocation problems, a given set of goods are assigned to agents in such a way that the social welfare is maximized, that is, the largest possible global worth is achieved. When goods are indivisible, it is possible to use money compensation to perform a fair allocation taking into account the actual contribution of all agents to the social welfare. Coalitional games provide a formal mathematical framework to model such problems, in particular the Shapley value is a solution concept widely used for assigning worths to agents in a fair way. Unfortunately, computing this value is a #P-hard problem, so that applying this good theoretical notion is often quite difficult in real-world problems. In this paper, we first review the application of the Shapley value to an allocation problem that models the evaluation of the Italian research structures with a procedure known as VQR. For large universities, the problem involves thousands of agents and goods (here, researchers and their research products). We then describe some useful properties that allow us to greatly simplify many such large instances. Moreover, we propose new algorithms for computing lower bounds and upper bounds of the Shapley value, which in some cases provide the exact result and that can be combined with approximation algorithms. The proposed techniques have been tested on large real-world instances of the VQR research evaluation problem.

关键词： Approximation algorithms

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Asynchronous parallel algorithms for nonconvex big-data optimization part II: Complexity and numerical results

arXiv

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arXiv 2017年

作者： Cannelli, Loris Facchinei, Francisco Kungurtsev, Vyacheslav Scutari, Gesualdo School of Industrial Engineering Purdue University United States Department of Computer Control and Management Engineering Antonio Ruberti University of Rome La Sapienza Roma Italy Dept. of Computer Science Faculty of Electrical Engineering Czech Technical University in Prague Czech Republic

We present complexity and numerical results for a new asynchronous parallel algorithmic method for the minimization of the sum of a smooth nonconvex function and a convex nonsmooth regularizer, subject to both convex and nonconvex constraints. The proposed method hinges on successive convex approximation techniques and a novel probabilistic model that captures key elements of modern computational architectures and asynchronous implementations in a more faithful way than state-of-the-art models. In the companion paper [3] we provided a detailed description on the probabilistic model and gave convergence results for a diminishing stepsize version of our method. Here, we provide theoretical complexity results for a fixed stepsize version of the method and report extensive numerical comparisons on both convex and nonconvex problems demonstrating the efficiency of our approach. Copyright © 2017, The Authors. All rights reserved.

关键词： Constrained optimization

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Clustering of XML documents based on structure and aggregated content 11

Clustering of XML documents based on structure and aggregate...

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11th International Conference on computer Engineering and Systems, ICCES 2016

作者： Rezk, Nermeen Gamal Sarhan, Amany Algergawy, Alsayed Electrical Engineering Dept. Faculty of Engineering Kafr Elshiekh Univ. Egypt Computer and Control Engineering Dept. Faculty of Engineering Tanta Univ. Egypt Institute of Computer Science Friedrich Schiller University of Jena Germany

ISBN: (纸本)9781509032679

The main objective of the work is to improve the clustering efficiency and performance when we deal with very big datasets. This paper aims to improve the quality of XML data clustering by exploiting more features extracted from source schemas. In particular, it proposes clustering approach that gathers both content and structure of XML documents to determine similarity between them. The content and structure information are concluded using two different similarity methods that are then grouped via weight factor to compute the overall document similarity. The structural similarity of XML data are derived from edge summaries while content features similarity are derived from aggregate of set of similarity measures;Jaccard, Cosine measure and Jensen-Shannon divergence in one algorithm. However, we also experimented using Jaccard distance as content measure with edge summaries to prove that using an aggregation of content similarity measures can further improve the results. The experiments prove that clustering of XML documents based on structure only information produce worse solution in homogenous environment, while in heterogeneous environment clustering of XML document produce better result when the structure and the content are combined. Results have shown that performance and quality of the proposed approach is better in comparison of both XEdge and XCLSC approaches. © 2016 IEEE.

关键词： XML

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Light-adaptive face registration based on drivers' video 15

Light-adaptive face registration based on drivers' video

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15th IEEE International Conference on Cognitive Informatics and Cognitive Computing, ICCI*CC 2016

作者： Zuojin, Li Peng, Jun Chen, Liukui Tirumala, Sreenivas Sremath Dept. of Measurement and Control Engineering Chongqing University of Science and Technology Chongqing China School of Engineering Computer and Mathematical Science Auckland University of Technology Auckland New Zealand

ISBN: (纸本)9781509038466

Under real driving conditions, the fatigue monitoring system based on drivers' video is highly affected by light environment, which deteriorates the registration of facial information and thus the accuracy of surveillance. This paper, on the basis of AAM (Active Appearance Model)-based face registration method, analyzes the reasons of its failure when lighting conditions change and proposes an improved AAM algorithm. The experiments show that the improved AAM method can well register driver's face under changing lighting environment, and thus improve the accuracy in fatigue state recognition based on drivers' videos. © 2016 IEEE.

关键词： Lighting

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Magnetic shocks and substructures excited by torsional Alfvén wave interactions in merging expanding flux tubes

arXiv

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arXiv 2018年

作者： Snow, B. Fedun, V. Gent, F.A. Verth, G. Erdélyi, R. School of Mathematics and Statistics University of Sheéld S3 7RH United Kingdom Department of Automated Control and Systems Engineering University of Sheéld S1 3JD United Kingdom Department of Computer Science ReSoLVE Centre of Excellence Aalto University PO Box 15400 HelsinkiFI-00076 Finland Dept. of Astronomy Eötvös L. University Pazmany Peter sétány 1/A BudapestH-1117 Hungary

Vortex motions are frequently observed on the solar photosphere. These motions may play a key role in the transport of energy and momentum from the lower atmosphere into the upper solar atmosphere, contributing to coronal heating. The lower solar atmosphere also consists of complex networks of ux tubes that expand and merge throughout the chromosphere and upper atmosphere. We perform numerical simulations to investigate the behaviour of vortex driven waves propagating in a pair of such ux tubes in a non-force-free equilibrium with a realistically modelled solar atmosphere. The two ux tubes are independently perturbed at their footpoints by counter-rotating vortex motions. When the ux tubes merge, the vortex motions interact both linearly and nonlinearly. The linear interactions generate many small-scale transient magnetic substructures due to the magnetic stress imposed by the vortex motions. Thus, an initially monolithic tube is separated into a complex multi-threaded tube due to the photospheric vortex motions. The wave interactions also drive a superposition that increases in amplitude until it exceeds the local Mach number and produces shocks that propagate upwards with speeds of approximately 50 km s1. The shocks act as conduits transporting momentum and energy upwards, and heating the local plasma by more than an order of magnitude, with peak temperature approximately 60;000 K. Therefore, we present a new mechanism for the generation of magnetic waveguides from the lower solar atmosphere to the solar corona. This wave guide appears as the result of interacting perturbations in neighbouring ux tubes. Thus, the interactions of photospheric vortex motions is a potentially significant mechanism for energy transfer from the lower to upper solar atmosphere. Copyright © 2018, The Authors. All rights reserved.

关键词： Magnetohydrodynamics

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Optimal distributed control for platooning via sparse coprime factorizations

Optimal distributed control for platooning via sparse coprim...

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American control Conference (ACC)

作者： Şerban Sabău Cristian Oară Sean Warnick Ali Jadbabaie Electrical and Computer Engineering Dept. Stevens Institute of Technology Hoboken NJ Automatic Control Dept. University “Politehnica” Bucharest Faculty of the Computer Science Department Brigham Young University Electrical and Systems Engineering Dept. University of Pennsylvania

We introduce a novel distributed control architecture for disturbances attenuation in heterogeneous platoons of linear and time-invariant autonomous agents that inherits the performance achievable by the leader-follower control policies. We provide a Youla-like parameterization for the class of all distributed controllers such that the sparsity constraints are imposed on the controllers' left coprime factors, outlining a new concept of structural constraints in distributed control. The proposed scheme lends itself to optimal controller design via norm based costs, it guarantees string stability and completely eliminates the accordion effect from the behavior of the platoon. The distributed controller is proven to attain global optimality for heterogeneous platoons and ℋ 2 costs and can easily reconfigure such as to remain optimal during formation merging/exiting maneuvers. The scheme is amenable to a GPS time base synchronization mechanism, allowing for the exact compensation of the time delays induced by the wireless communications.

关键词： Vehicles Standards Decentralized control Stability analysis Linear systems Transfer functions Electronic mail

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Inexpensive robot for experimental validation of planning and control algorithms

Inexpensive robot for experimental validation of planning an...

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International Conference on System Theory, control, and Computing (ICSTCC)

作者： José Lamarca Marius Kloetzer Cristian Mahulea Dept. of Computer Science and Systems Engineering University of Zaragoza Spain Dept. of Automatic Control and Applied Informatics Technical University of Iasi Romania Aragón Institute for Engineering Research University of Zaragoza Spain

ISBN: (纸本)9781509027217

This paper describes the structure of a mobile robot suitable for laboratory experiments. The robot is developed with the ideas of minimizing the production costs and of executing motion commands received from an external computer that runs the (possible computational intensive) planning algorithms. The proposed system is a differential wheeled robot built based on an Arduino platform, it has a small physical size and it is capable of wireless communication. These characteristics make it useful for validating planning algorithms for mobile robots in computer-guided laboratory experiments, while lowering the expenses required by such a setup. Moreover, in order to compensate the communication delay between the central computer and the robot, an estimation algorithm is implemented on the robot for obtaining a smoother motion.

关键词： Mobile robots Wheels computers Planning Trajectory Pins

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Modeling peer assessment as a personalized predictor of teacher's grades: The case of OpenAnswer

Modeling peer assessment as a personalized predictor of teac...

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International Conference on Information Technology Based Higher Education and Training, ITHET

作者： Maria De Marsico Andrea Sterbini Marco Temperini Computer Science Dept. Sapienza University Rome Italy Dept. of Computer Control and Management Engineering Sapienza University Rome Italy

ISBN: (纸本)9781509007790

Questions with open answers are rarely used as e-learning assessment tools because of the resulting high workload for the teacher/tutor that should grade them. This can be mitigated by having students grade each other's answers, but the uncertainty on the quality of the resulting grades could be high. In our OpenAnswer system we have modeled peer-assessment as a Bayesian network connecting a set of sub-networks (each representing a participating student) to the corresponding answers of her graded peers. The model has shown good ability to predict (without further info from the teacher) the exact teacher mark and a very good ability to predict it within 1 mark from the right one (ground truth). From the available datasets we noticed that different teachers sometimes disagree in their assessment of the same answer. For this reason in this paper we explore how the model can be tailored to the specific teacher to improve its prediction ability. To this aim, we parametrically define the CPTs (Conditional Probability Tables) describing the probabilistic dependence of a Bayesian variable from others in the modeled network, and we optimize the parameters generating the CPTs to obtain the smallest average difference between the predicted grades and the teacher's marks (ground truth). The optimization is carried out separately with respect to each teacher available in our datasets, or respect to the whole datasets. The paper discusses the results and shows that the prediction performance of our model, when optimized separately for each teacher, improves against the case in which our model is globally optimized respect to the whole dataset, which in turn improves against the predictions of the raw peer-assessment. The improved prediction would allow us to use OpenAnswer, without teacher intervention, as a class monitoring and diagnostic tool.

关键词： IEC Electromagnetic interference IEC Standards

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Considerations regarding security issues impact on systems availability

Considerations regarding security issues impact on systems a...

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International Conference on Electronics, computers and Artificial Intelligence (ECAI)

作者： Emil Pricop Sanda Florentina Mihalache Nicolae Paraschiv Jaouhar Fattahi Florin Zamfir Automatic Control Computers & Electronics Department Petroleum-Gas University of Ploiesti Ploiesti Romania Dept. of Computer Science & Software Engineering Université Laval Québec Canada

control systems behavior can be analyzed taking into account a large number of parameters: performances, reliability, availability, security. Each control system presents various security vulnerabilities that affect in lower or higher measure its functioning. In this paper the authors present a method to assess the impact of security issues on the systems availability. A fuzzy model for estimating the availability of the system based on the security level and achieved availability coefficient (depending on MTBF and MTR) is developed and described. The results of the fuzzy inference system (FIS) are presented in the last section of the paper.

关键词： Security Reliability control systems Wireless sensor networks Fuzzy logic Safety Network topology

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Quantum key distribution with setting-choice-independently correlated light sources

arXiv

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arXiv 2018年

作者： Mizutani, Akihiro Kato, Go Azuma, Koji Curty, Marcos Ikuta, Rikizo Yamamoto, Takashi Imoto, Nobuyuki Lo, Hoi-Kwong Tamaki, Kiyoshi Graduate School of Engineering Science Osaka University Toyonaka Osaka560-8531 Japan NTT Communication Science Laboratories NTT Corporation 3-1 Morinosato Wakamiya Atsugi-Shi Kanagawa243-0198 Japan NTT Research Center for Theoretical Quantum Physics NTT Corporation 3-1 Morinosato-Wakamiya Atsugi Kanagawa243-0198 Japan NTT Basic Research Laboratories NTT Corporation 3-1 Morinosato-Wakamiya Atsugi-Shi243-0198 Japan EI Telecomunicacion Department of Signal Theory and Communications University of Vigo VigoE-36310 Spain Center for Quantum Information and Quantum Control Department of Physics and Dept. of Electrical and Computer Engineering University of Toronto TorontoM5S 3G4 Canada Graduate School of Science and Engineering for Education University of Toyama Gofuku 3190 Toyama930-8555 Japan

Despite the enormous theoretical and experimental progress made so far in quantum key distribution (QKD), the security of most existing QKD implementations is not rigorously established yet. A critical obstacle is that almost all existing security proofs make ideal assumptions on the QKD devices. Problematically, such assumptions are hard to satisfy in the experiments, and therefore it is not obvious how to apply such security proofs to practical QKD systems. Fortunately, any imperfections and security-loopholes in the measurement devices can be perfectly closed by measurement-device-independent QKD (MDI-QKD), and thus we only need to consider how to secure the source devices. Among imperfections in the source devices, correlations between the sending pulses are one of the principal problems. In this paper, we consider a setting-choice-independent correlation (SCIC) framework in which the sending pulses can present arbitrary correlations but they are independent of the previous setting choices such as the bit, the basis and the intensity settings. Within the framework of SCIC, we consider the dominant uctuations of the sending states, such as the relative phases and the intensities, and provide a self-contained information theoretic security proof for the loss-tolerant QKD protocol in the finite-key regime. We demonstrate the feasibility of secure quantum communication within a reasonable number of pulses sent, and thus we are convinced that our work constitutes a crucial step toward guaranteeing implementation security of QKD. Copyright © 2018, The Authors. All rights reserved.

关键词： Quantum cryptography

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